Spinning solution



trite-d. States -Patent 2,875,079 *SPINNING SOLUTION Robert E. Clark, Madison, Tenn., assignor to E. I. do

Pontde Nemonrs and Company, corporation of Delaware No Drawing. Application March 4, 1957 set-m No. 643,510

6 Claims. (Cl. 106-165) This invention relates to a novel and useful composiwhere the yarn is normally unacceptable due to low and variable luster. Another object is to provide a viscose spinning solution which is suitable for the preparation of lustrous textile rayon filaments.

These objects are accomplished by the present inven-f tion which provides an improvement in the process for the preparation of a regenerated cellulose filament by extruding viscose into an acid coagulating and regenerating bath, which comprises incorporating into the viscose,

prior to extruding, from at least about 0.02 to about 0.10% by weight, calculated as the sodium salt, of a soluble salt of a sulfated fatty acid having atleast 10 carbon atoms and from about 0.05 to about 0.10% by weight, calculated as sodium sulfite, of a soluble sulfite. By the term incorporating is meant that the additives are present in the viscose at the time of extrusion into the acidbath. The additives, therefore, may be added directly to the viscose or the viscose ingredients at anystage of the viscose preparationor theyjmay. be formed in situ by the addition of other compounds which are converted by the alkali of the viscose into the soluble additives. The term soluble is used to designate that the additive is soluble to at least the required extent in the viscose solution. The term sulfated fatty acid is used to signify the reaction product of sulfuric acid and an ethylenically unsaturated or hydroxyl substituted .fatty acid. These sulfated fatty acids all have the gen eral formula (HOSO ),,-R-COOH wherein n is a small whole integer and R is an aliphatic group of at least 9 carbon atoms. The prepara tion of these sulfated fatty acids is described in British Patent No. 293,480 and also in of Fats and Waxes by Hilditch, 2nd edition, pages 398 to 400 (1941). The salts of the sulfated fatty acids are formed by reacting the sulfated acid with an alkali metal hydroxide such as sodium or potassium hydroxide. The salt may also be formed in situ by the addition of the sulfated fatty acid directly to the viscose in which case the alkali of the viscose converts the acid to the sodium salt.

In the preferred embodiment of this invention a C fatty acid is employed. When oleic acid is sulfated the resulting compound has the structure Wilmington, Del., a

' 2,875,079 1 j fiiiited l eb. a4, 195s This compound 'is' then incorporated into the viscose or theviscose ingredients, generally as'the sodium salt, to give a viscose solutionhaving the desired concentration of the sulfated fatty acid.

The soluble sulfite' may be addedto'the viscose or viscose ingredients as sodium sulfite'or sodium bisulfite or other soluble sulfite such as potassium sulfite or bisulfite. If the bisulfite is added it is converted to the sulfite by action of the alkali in the viscose. -A preferred method of addition of the sulfite, byreason of economyyis the addition ofmetabisulfite, Na,s,o,, whichin aqueous sulfite, of a soluble sulfi te. d W d v d The invention will now be further described in the.

solution forms sodium biSuIfiteNaHSO the sodium sodium sulfite Na,so,, by

bisulfite being converted to the alkali in the viscose; v

The present invention also provides .an .nnpr oved spinning solution. which-comprises viscose containing at least about 0.02 to about 0.10% .by weight, calculated as the sodium salt, .ofa solublesalt of'a sulfated fattyacid having at least 10 carbon atoms and from about 0.05 to about 0.10% byweight, calculated as sodium following specific examples, which areto be regarded solely as illustrative, and not as restricting the scope of theinvention. 3

Example] Alkali cellulose is preparedin theconventional manner by steeping sheets of wood pulp in caustic solution,

lpressing to remove the excess caustic andshredding.

The alkali cellulose is aged and then xanthated using 33% carbon disulfite, based on the air dried weight,

ofthe pulp. The xanthate is dissolved in dilute sodium hydroxide solution to form viscose'containing 7.0% recoverable cellulose and 6.0% alkali, calculated as sodium hydroxide.

of sulfated oleic acid (sold under the'trade name of. -Prestabit Oil V and sufficient sodium metabisulfite, Nil- 5 0 toform 0.074% sodiumsulfite, is added tothe Viscose. 4 d The viscose is filtered, deaerated and-ripened to a salt index of 4.5 to.4.7 and a viscosity of 45 poises at which time it is extruded through a 40 hole spinneret into a coagulating and regenerating bath maintained at 521C. and containing9.8% sulfuric acid, 19.8% sodium sulfate and 3.5% zinc sulfate to form a yarn of 150 denier.

The yarn is passed through the bath by means of suitable roller guides, then up to and around a feed wheel and The Industrial Chemistry cakes so prepared are down into a centrifugal spinning bucket where it is wound into a cake at a speed of yards per minute. A small stream of water at 35 C. is applied. to the yarn at the feed wheel to insure good cake formation.

The cakes are washed free of acid by showering with soft water, desulfurized with a dilute sodium carbonate solution according to the process of U. S. Patent 1,931,266, washed with soft water for about 4 hours to remove the desulfurizing solution and bleached with a chlorine-water bleach according to the process of U. 8. Patent 2,116,210. The cakes are then showered for about 4 hours with a conventional finish solution containing 0.1% soluble starch, 0.05% citric acid and 0.2% light mineral oil (liquid petrolatum), dispersed in the solution. The cakes are dried by heating in the conventional manner.

To judge the luster of the cakes, yarn from the inside, center and outside of the cake is wound on dull black cards about 1% x 6 inches in s e. The cards are then viewed obliquely in artificial light. The yarn, when viewed in this manner, high degree of uniformity, and substantially all of the commercially acceptable.

During mixing 0.05% of the sodium salt shows a high level of luster, a

and lev l.-

The procedure, of Example, 1 is again fo lowed, emit in both the sodium salt of sulfated oleic acid and the sodium metabisulfite. The yarn prepared in this manner shows a low level of luster and a low degree of uniformity. Sub? stantially all ofthe, caltes are commercially unacceptable. Example 3 harro du a Exa pl l is, again low u i the-s dium salt o s l ated qle c a i (soldv nder. h tradeuame Qt iPQ FQh I Q l. Th qd ni i lfi e s emi ed n th seremp e- Foami g o urs r ng t e, deaeration step and. it is too. severe. t0 permi mm rcial p rat n at he p ewa- I! dd ion a su ut l n m e of the ca es prepar d n hi man er crav d.- be una ceptab e. with r gard t9 Lus er ni m:

Example Q T e rqs d re at; lectric si sain follo d u in u iici it me a su fite o, 62 .11. 045% ad u u e ii he co e qd mi. a t su a oleic m d s. however, omitted. Dif ficulty is encountered in the spinning step of the process due to slow coagulation and ex: cessive formation of sulfur sludge also, occurs.v A substantial number of the cakes prepared in this manner also proved to be unacceptable with regard to, luster uniforrm. ity and level.

The examples thus show that yarns spun from viscose containing the sulfated fatty acid and sulfite in accordance with this invention are superior with regard to level and uniformity of luster as compared to yarns spun in the absence of these compounds or with only; one of them present. r

While the addition of a sulfatedfatty acid and a'soluble sulfite in accordance with this invention is useful in all the conventional viscose-spinning processes, it is particularly useful in processes designed to produce yarns of higherstrength and'hi'gh'er silk factor. Such processes involve the useof higher than normal concentrations of 38 higher saltindex and/or higher than normal concentrations of metal salts, such as zinc sulfate, in the bath. Since these conditions usually result in yarns of lower and more variable luster, the yarn is not commercially acceptable. By the practice of this invention, however, the luster of-th'ese yarns, are improved to the extent that the yarns are commercially acceptable and the advantages of; higher strength and higher silk factor may be realized. The re nt inyention,7thetefore, is par-tic camera ularly applicable to processes wherein viseoce.-- (sa'-ltof at least 4.2), which has been prepared with more than 31% (3S: and which contains 6' to 8% recoverable cellulose and 4 to 8% alkali, is extruded into a coagulating.

and regenerating bath containing 7 to 12% sulfuric acid, 15 to 25% sodium sulfate, and 2 to 10% zinc sulfate.

The yarns prepared by this invention are useful wherever conventional textile rayon yarns are used, such as wearing apparel, draperies and the, like.

Many modifications will be apparent to those, skilled n he art from the. d g the havel wit out a. parture from the inventive concept,

What is claimed is: I

1. In the process for the preparation of a regenerated cellulose filament by extruding v iscose into an acid coagulating and regenerating bath, the improvement which comprises incorporating into the viscose, prior to extruding, from at least about 0.02 to about 0.10% by e ght, calculated s the s d um. a f sa ab e. s l efsul eted att ac d ha n at eas 1.0; c. and; r m ab ut 0-9 about 0 .0% y were at t essq iu nsul t o a sq ub es l ite- V V 2.1 The process of claim 1 wherein the sulfated fatty acid is a sulfated fatty acid containing 18 carbon atoms;

3. The process of claim 1 wherein the sulfatedfatty acid is sulfated oleic acid.

4. A spinning solution consisting essentially of viscose containing at least about 0.02 to about 0.10% by weight, calculated as the sodium salt, of a soluble salt of a s'uh. fated fatty acid having at least 10 carbon atoms and from, about 0.05' to about 0.10%v by weight, calculated as, sodium sulfite, of a soluble sulfite.

5'. The spinning solution of cla m 4 wherein the 1111 fated fatty acid iswa sulfatecl fatty acid containing 1 8 car-' b oms- V itp uninsso iqn c im 4 he ein. the. stile e rfa y 3Q l 8$1 1fated o e acid- References Cited in the file of this patent UNITED STATES PATENTS QTHE'R' REFERENCES undies: industrial. Fa and. axe 1 hird'editinnt 19.42,, pages 491M431. 

1. IN THE PROCESS OF THE PREPARATION OF A REGENERATED CELLULOSE FILAMENT BY EXTRUDING VISOCE INTO AN ACID COAGULALTING AND REGENERATING BATH, THE IMPROVEMENT WHICH COMPRISES INCORPORATING INTO THE VISCOSE, PRIOR TO EXTRUDING, FROM AT LEAST ABOUT 0.20 TO ABOUT 0.10% BY WEIGHT, CALCULATED AS THE SODIUM SALT, OF A SOLUBLE SALT OF A SULFATED FATTY ACID HAVING AT LEAST 10 CARBON ATOMS AND FROM ABOUT 0.05 TO ABOUT 0.10% BY WEIGHT, CALCULATED AS SODIUM SULFITE, OF A SOLUBLE SULFITE. 